Initial conditions for natural inflation

Journal Article · Thu Jul 15 04:00:00 EDT 1993 · Physical Review, D (Particles Fields); (United States)

DOI:https://doi.org/10.1103/PhysRevD.48.946· OSTI ID:6426795

Knox, L ^[1]; Olinto, A ^[2]

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1. Department of Physics, Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637 (United States)
2. Department of Astronomy and Astrophysics, Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637 (United States)

We investigate the issue of initial conditions for natural inflation in a homogeneous universe. Unlike many inflationary models, the pseudo Nambu-Goldstone boson nature of the inflaton field provides a natural measure for the phase space of initial conditions. We study the effects of the inflaton kinetic term numerically, and show that it shifts the range of initial field values which lead to successful inflation without altering the size of that range. The fraction of phase space in the successful range is determined by the spontaneous symmetry-breaking scale [ital f] and is 0.7, 0.2, and 3[times]10[sup [minus]3] for [ital f]=3[ital M][sub Pl], [ital M][sub Pl], and [ital M][sub Pl]/2 respectively. Natural inflation becomes similar to chaotic inflation for values of [ital f][approx gt][ital M][sub Pl], and for [ital f][approx lt][ital M][sub Pl] it is more akin to new inflation.

• DOE Contract Number: FG02-91ER40606
• OSTI ID: 6426795
• Journal Information: Physical Review, D (Particles Fields); (United States), Journal Name: Physical Review, D (Particles Fields); (United States) Vol. 48:2; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

662100* -- General Theory of Particles & Fields-- (1992-)
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
BOSONS
COSMOLOGICAL MODELS
ELEMENTARY PARTICLES
GOLDSTONE BOSONS
INFLATIONARY UNIVERSE
MATHEMATICAL MODELS
MATHEMATICAL SPACE
NUMERICAL SOLUTION
PHASE SPACE
POSTULATED PARTICLES
SPACE
SYMMETRY BREAKING